Chronic pain can be predicted within days of a whiplash injury in some patients. Brain scans taken in the first days after the crash showed a pattern. People with more anxiety had stronger crosstalk between the hippocampus and cortex. They were the ones more likely to develop chronic pain.
Summary: A new study scanned the brains of whiplash patients. People with more anxiety after the injury showed more crosstalk between the hippocampus and cortex. That crosstalk locks in the memory of the injury (consolidation). These people are more likely to develop chronic pain.
Chronic pain is the most common health problem in the US. About one-fourth of adults report it. Chronic pain is pain that lasts for three months or more. It is pain that outlasts the problem that first caused it.
There are many reasons chronic pain is so hard to manage. It is pain that outlasts the problem that first caused it. So many people with chronic pain are fairly healthy adults with normal lab tests. Even when they have some health problem, it is often unrelated to their pain.
Since doctors cannot say why the pain is happening, they also find it hard to cure. Of course, doctors use many treatments to manage it, both drug (pharmacological) and non-pharmacological therapies.
Can you predict chronic pain after a whiplash injury?
Many people still have pain for months and even years after the injury has fully healed. But this does not happen to everyone, only to some. So these people might be different from others. There must be a reason chronic pain is more likely in some. If science could learn why pain becomes chronic, or who is at greater risk, it could find ways to prevent it.
That is exactly what one new study does. It found a reliable way to spot people at greater risk of developing chronic pain.
This new study found a way to judge the risk of chronic pain within a few days of an injury. The results of this study were published in Nature Mental Health.
Chronic pain often outlasts the physical injury that first caused it. So researchers believe that, in many cases, it comes from certain brain changes or negative emotional learning.
Studies also show that people with certain personality traits are more likely to develop chronic pain. People who feel more anxiety after an injury are also more likely to have chronic pain.
In this study, researchers wanted a more objective way to judge the risk. So they scanned the brains of 110 patients with whiplash injuries (within the first three days of injury). They saw that those who went on to chronic pain had stronger crosstalk between the hippocampus and cortex.
The cortex stores long-term memories. The hippocampus plays a significant role in starting that storage. The researchers also saw more anxiety or emotional response in these patients, with more activity in the amygdala, a brain area tied to fear and emotion.
So researchers found that people with more anxiety in these early days were more likely to go through specific brain changes that lead to chronic pain.
This also means the first few days matter for preventing these brain changes. Researchers say those early days need a special focus on preventing anxiety. This may help keep pain from becoming chronic.
There could be many ways to manage anxiety in those early days. It could be with medications or with non-pharmacological means. The goal is to stop the extra crosstalk between the hippocampus and the cortex. That prevents pain consolidation.
In many cases of chronic pain, the brain plays a big role. The brain has a much greater role in chronic pain than in acute pain. It is the brain that decides whether certain motions will hurt. So in those early days, care must manage the injury and associated pain, along with the anxiety associated with that injury.
Related reading: coping with fear and flashbacks after a crash.
Frequently asked questions
Can whiplash cause chronic pain?
Yes, in some people. Many whiplash patients recover, but some keep hurting for months or years after the injury itself has healed. Brain scans of 110 whiplash patients were taken within three days of the injury. Those who went on to chronic pain had stronger crosstalk between the hippocampus and the cortex. That is the brain’s system for storing long-term memories.
Do you ever fully recover from whiplash?
Many do, but not everyone. Many people continue to have pain for months and even years after a complete recovery from the injury. That pain outlasts the problem that caused it, often in otherwise healthy adults with normal lab tests. The brain plays a much larger role in chronic pain than in acute pain. It decides which motions will hurt.
Why does anxiety after a whiplash injury raise the risk of chronic pain?
People with more anxiety in the first days after a whiplash injury showed greater activity in the amygdala and stronger crosstalk between the hippocampus and cortex. That crosstalk helps lock in the memory of the injury, a process called pain consolidation. Those patients were more likely to develop chronic pain. That is why the first few days after the injury matter.
How can you lower the risk of chronic pain after whiplash?
The first few days matter most. Care in that window should treat the injury and its pain and also the anxiety that comes with it. Anxiety can be managed with medications or with non-pharmacological approaches. Calming it early aims to prevent the brain changes that turn a fresh injury into lasting pain. The key change is the extra hippocampus-cortex crosstalk.
Source:
Branco, P., Bosak, N., Vigotsky, A. D., Granovsky, Y., Yarnitsky, D., & Apkarian, A. V. (2024). Hippocampal functional connectivity after whiplash injury is linked to the development of chronic pain. Nature Mental Health, 2(11), 1362–1370. https://doi.org/10.1038/s44220-024-00329-8
Medically reviewed by Dr. Gurpreet Singh Padda, MD, MBA, MHP — Board Certified in Anesthesiology, Pain Medicine, Interventional Pain Management, Addiction Medicine, and Obesity Medicine.
